Nick Calabrese testified to the Feds that Frank Calabrese Sr. made the silencer and that Angelo disposed of the gun that was found. This would point to LaPietra being the guy who pulled the trigger.

Giancana and Angelo knew eachother during this time since Angelo was working as a soldier, assassin, and enforcer under Giancana's right hand man Fiore "FiFi" Buccieri and Joey Aiuppa who would succeed Giancana, as boss of the outfit. This created trust between Angelo and Giancana. Shortly after Giancana was killed, Angelo is appointed Capo of the Chinatown/26th street regime. What better way to reward a loyal and dependable soldier for what he had done by making him Capo of his own crew. A similar situation happened with John Gotti out in New York when he killed Castellano.

Thoughts?